When objects, e.g., food or home appliances, vulnerable to foreign substances such as dust or rain are loaded in a cargo truck, for example, a vinyl cover should be spread thereon and then fixed with a rope to protect the loaded objects from foreign substances. For example, when a garbage truck carries garbage, a cover is provided on a container thereof and a person manually opens or closes the cover or piston rods of cylinders are connected to the cover to forcibly open or close the cover, thereby preventing the garbage from escaping from the container.
For example, rocks fallen from a dump truck may not only obstruct traffic but also damage nearby vehicles. The above problem occurs because a cover is not firmly fixed or no cover is used.
Korean Patent Publication No. 1020110099565 (Sep. 8, 2011) discloses an automatic cover apparatus of a container of a cargo truck, the apparatus including a cover, fixture wires fixed along two edges of the cover and having rear ends protruding from a rear part of the cover, a pair of rotation arms hinge-coupled to bottom center parts of two sides of the container to reciprocate in forward and backward directions of the container, a drum rotatably coupled to upper sides of the rotation arms and connected to the protruding rear ends of the fixture wires to wind or unwind the cover when the rotation arms reciprocate, tension springs provided at the two sides of the container to elastically support the rotation arms toward a rear part of the container, and a driver provided between the rotation arms and the drum to rotate the drum.
Korean Utility Model Registration No. 2001976490000 (Jul. 14, 2000) discloses a cover apparatus of a container of a cargo truck, the apparatus including support rods 1 reciprocating forward and backward with respect to support rod holders 5 connected to ends of the support rods 1 at bottom center parts of sides of the container, and provided at the connected ends of the support rods 1, upper motors 6 and 6′ provided at ends of a shaft interconnecting the support rods 1 and fixed to ends of the support rods 1, a shaft connected to the upper motors 6 and 6′, a drum 8 connected to the shaft, a cover wound around the drum 8, a side motor 11 provided under the support rod 1 connected to an end of the bottom center parts, a gear 12′ provided on the side motor 11, a reducer gear 12 provided at an end of a support rod shaft 16, a chain 13 interconnecting the gears 12 and 12′, bearings 15 and 15′ provided on the support rod shaft 16, and a spring 4 provided between the bearings 15 and 15′, wherein one end of the spring 4 is connected to the cargo truck and another end of the spring 4 is connected to an auxiliary support rod 14.
Korean Patent Registration No. 1004390180000 (Jun. 24, 2004) discloses an automatic cover apparatus of a container of a cargo truck, and a method of opening or closing the same, the apparatus including support rod rotating devices 5 connected to ends of support rods 1 provided at two sides of a base panel where the container is mounted, and driven using springs provided under the connected support rods 1, the support rods 1 reciprocating forward and backward with respect to the support rod rotating devices 5 using the springs, auxiliary support rods 1′ coupled to ends of the support rods 1 using hinges 11, air cylinders 12 provided at upper parts of the support rods 1 to fold and unfold the auxiliary support rods 1′, a cover holder 2 provided at ends of the auxiliary support rods 1′, a cover winder 3 and a cover support rod 4 provided between the driver's seat and the container, and a cover 6 connected to the cover holder 2 and the cover winder 3.
Korean Patent Registration No. 1008494710000 (2008 Jul. 24) discloses an automatic cover apparatus of a container of a cargo truck, in which ends of support rods are coupled to bottom center parts of two sides of the container, a motor is provided at a lower part of the support rods to rotate the support rods, a drum for winding a cover is connected to a shaft interconnecting upper parts of the support rods, and motors are provided at ends of the support rods to rotate the drum such that the drum winds up the cover to open the container, the motors being driven in reverse such that the drum spreads the cover to close the container. Ends of wires are connected to wire holders provided at two ends of the drum and other ends of the wires pass through cover edge sewing parts, and rubber bands are connected to sides of the cover to firmly fix the sides of the container cover, thereby preventing falling of loaded objects from sides of the container.
Korean Patent Publication No. 1020000053861 (2000 Sep. 5) discloses an automatic cover apparatus of a container of a dump truck, the apparatus being capable of preventing escaping of loaded objects and scattering of dust from the container of the dump truck. In consideration of problems of conventional automatic cover apparatuses, e.g., breakdown and reverse operation of an automatic cover apparatus due to limited motor capacity and reduction in speed, and loosening of a cover due to a large number of uses and weakening of spring tension, a motor and a reducer are not used and the cover apparatus is driven using the distance between the container and a body of the dump truck when the container is lifted. As such, breakdown of conventional products due to a motor and a reducer is fundamentally prevented and a problem caused when a spring reaches a fatigue limit is solved.